This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | -1 |
| 3 | -11 |
| 4 | -239 |
| 5 | -17059 |
| 6 | -2145689 |
| 7 | -412595231 |
| 8 | -111962826751 |
| 9 | -40590007936199 |
| 10 | -18900753214178609 |
| 11 | -10974885891916507219 |
| 12 | -7765167486697279401071 |
| 13 | -6571694718107813687003051 |
| 14 | -6551841491106355785902247049 |
| 15 | -7597507878436131044487467850599 |
| 16 | -10136619271768255373949409579309439 |
| 17 | -15416099624633773180711565727641136271 |
| 18 | -26508391106594400233543066679525341764961 |